In bdrv_open_inherit(), the filename is refreshed after opening the
backing file, but we neglected to do the same when the backing file
changes later.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block.c b/block.c
index dd38e71..cb57370 100644
--- a/block.c
+++ b/block.c
@@ -1938,6 +1938,8 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
         bdrv_unref(backing_hd);
     }
 
+    bdrv_refresh_filename(bs);
+
 out:
     bdrv_refresh_limits(bs, NULL);
 }
-- 
1.8.3.1